The present invention relates to hair dryers and, more particularly, to a hair dryer having a heating source that emits heat and light having wavelengths in the visible spectrum.
When hair is wet, it becomes densely packed. As such, it is difficult for heat to penetrate wet hair to dry it. Ironically, hair that is wettest is most inefficient to dry through conventional means.
Traditional hair drying systems that rely on fan-forced convection heat are unable to get heat into the underlying hair fibers within tresses of densely packed wet hair. It is a well known and documented problem that hair dryers often damage the outermost hair fibers before the inner fibers are even dry. This damage is caused by the over heating and over drying effects of hot air.
Several attempts have been made to increase the rate at which under-lying wet hair is dried. These include coupling of the dryer to a brush or comb attachment that mechanically separates the hair fibers as hot air is blown at the hair. Various hot air injection attachments have also been devised for blow dryers in an attempt to address this problem, which include hollow tines that feed hot air directly into the wet tresses. In general, these attachments and accessories have improved the problem, but caused the hair dryer to be more complicated than desired in both design and use, and rendered the hair dryer more specifically dedicated to a particular hair style, which reduced its versatility and value. Also, the physical disturbance of the hair tresses by such attachments and accessories tend to "fluff" the hair and provide a style that may not be desirable.
Additional attempts to heat and dry the underlying hair fibers with infrared heat have been made with limited success. Although the infrared rays do penetrate the wet hair tresses more effectively and dry the hair more efficiently, excessive exposure to infrared rays can be damaging to the skin, scalp, and hair follicles, and its invisibility does not provide for a very effective indicator of its presence. It is found that users do not respect the danger of invisible infrared heat until they feel the heating of the scalp, after the hair is already damaged and the scalp has been overexposed.